(a) Field of the Invention
The present invention relates to an LED lighting apparatus. More particularly, the present invention relates to an LED lighting apparatus of a closed type.
(b) Description of the Related Art
Since a light emitting diode (LED) as a light semiconductor using a compound semiconductor was invented, a white LED has been rapidly developed in an aspect of efficiency of the emitted light compared with input power.
Thanks to the development of this light-efficient white LED, a characteristic that much light is emitted through low energy consumption is ensured, and currently, the white LED is replacing traditional light sources such as incandescent, fluorescent, and high-pressure discharge lamp light sources and is becoming widely used for lighting.
Of these, fluorescent lamps having particularly high luminous efficacy have been used as the most efficient lighting, until recently, but the efficiency of the LED lighting has overtaken that of the fluorescent lamps such that the fluorescent lamps are starting to be replaced by the LED lighting.
On the other hand, the LED lighting apparatus is penetrated by foreign matter such as dust and insects through a gap when using the device for a long period of time, and the foreign matter builds up inside the device such that the emission of light is shielded, thereby causing a reduction in illumination, and an electrical circuit failure may be generated by the foreign matter penetrated therein.
Also, in a case of outdoor use, a waterproofing function of the device is required, and for the sealing structure for the waterproofing, an expensive apparatus structure must be configured, such that the structure is complex and costly.
As a result, an LED lighting apparatus having an effective closed structure for waterproofing, dust-proofing, and blocking insects needs to be developed.
On the other hand, the LED lighting apparatus must have a wide light distribution angle in a case of a low ceiling and must have a narrow light distribution angle to transmit the light a long distance in a case of a high ceiling, such that it is necessary to differentiate the light distribution angle depending on the installation location, and for this, a complicated mechanism for the reflection or the refraction of light must be added inside the apparatus.
Without the complex addition mechanism, an LED lighting apparatus having an economical and simple internal structure to more effectively cope with the change of the light distribution angle needs to be developed.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.